/*
 * Copyright (c) 2007, 2021, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */
/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.sun.org.apache.xpath.internal.functions;

import com.sun.org.apache.xpath.internal.XPathContext;
import com.sun.org.apache.xpath.internal.objects.XObject;
import com.sun.org.apache.xpath.internal.objects.XString;

/**
 * Execute the Translate() function.
 *
 * @xsl.usage advanced
 */
public class FuncTranslate extends Function3Args {
    static final long serialVersionUID = -1672834340026116482L;

    /**
     * Execute the function.  The function must return
     * a valid object.
     *
     * @param xctxt The current execution context.
     * @return A valid XObject.
     * @throws javax.xml.transform.TransformerException
     */
    public XObject execute(XPathContext xctxt) throws javax.xml.transform.TransformerException {

        String theFirstString = m_arg0.execute(xctxt).str();
        String theSecondString = m_arg1.execute(xctxt).str();
        String theThirdString = m_arg2.execute(xctxt).str();
        int theFirstStringLength = theFirstString.length();
        int theThirdStringLength = theThirdString.length();

        // A vector to contain the new characters.  We'll use it to construct
        // the result string.
        StringBuffer sbuffer = new StringBuffer();

        for (int i = 0; i < theFirstStringLength; i++) {
            char theCurrentChar = theFirstString.charAt(i);
            int theIndex = theSecondString.indexOf(theCurrentChar);

            if (theIndex < 0) {

                // Didn't find the character in the second string, so it
                // is not translated.
                sbuffer.append(theCurrentChar);
            } else if (theIndex < theThirdStringLength) {

                // OK, there's a corresponding character in the
                // third string, so do the translation...
                sbuffer.append(theThirdString.charAt(theIndex));
            } else {

                // There's no corresponding character in the
                // third string, since it's shorter than the
                // second string.  In this case, the character
                // is removed from the output string, so don't
                // do anything.
            }
        }

        return new XString(sbuffer.toString());
    }
}
